/* bzflag
 * Copyright (c) 1993-2020 Tim Riker
 *
 * This package is free software;  you can redistribute it and/or
 * modify it under the terms of the license found in the file
 * named COPYING that should have accompanied this file.
 *
 * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include "common.h"

// interface header
#include "OpenGLFramebuffer.h"

// system headers
#include <map>
#include <string>

// common headers
#include "OpenGLGState.h"

void OpenGLFramebuffer::initFramebuffer()
{
    glGenFramebuffers(1, &framebuffer);
    glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);

    glGenRenderbuffers(1, &renderbuffer);
    glBindRenderbuffer(GL_RENDERBUFFER, renderbuffer);
    glRenderbufferStorageMultisample(GL_RENDERBUFFER, msaaLevel, GL_RGB,
                                     width, height);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
                              GL_RENDERBUFFER, renderbuffer);

    glGenRenderbuffers(1, &depthRenderbuffer);
    glBindRenderbuffer(GL_RENDERBUFFER, depthRenderbuffer);
    glRenderbufferStorageMultisample(GL_RENDERBUFFER, msaaLevel,
                                     GL_DEPTH24_STENCIL8,
                                     width, height);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT,
                              GL_RENDERBUFFER, depthRenderbuffer);

    if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
        printf("Multisample framebuffer incomplete.\n");

    glBindFramebuffer(GL_FRAMEBUFFER, 0); // break the binding
}

void OpenGLFramebuffer::destroyFramebuffer()
{
    glDeleteRenderbuffers(1, &renderbuffer);
    glDeleteRenderbuffers(1, &depthRenderbuffer);
    glDeleteFramebuffers(1, &framebuffer);
}

OpenGLFramebuffer::OpenGLFramebuffer() : contextActive(false), msaaLevel(1),
    width(1), height(1),
    renderbuffer(0), depthRenderbuffer(0),
    framebuffer(0)
{
    OpenGLGState::registerContextInitializer(freeContext, initContext,
            (void*)this);
}

OpenGLFramebuffer::~OpenGLFramebuffer()
{
    OpenGLGState::unregisterContextInitializer(freeContext, initContext,
            (void*)this);
}

void OpenGLFramebuffer::checkState(int newWidth, int newHeight,
                                   int newMSAALevel)
{
    if(width != newWidth || height != newHeight || msaaLevel != newMSAALevel)
    {
        width = newWidth;
        height = newHeight;
        msaaLevel = newMSAALevel;

        if(contextActive)
        {
            destroyFramebuffer();
            initFramebuffer();
        }
    }
}


void OpenGLFramebuffer::freeContext(void* self)
{
    if(OpenGLGState::getMaxSamples() == 1)
        return;

    if(! ((OpenGLFramebuffer*)self)->contextActive)
        return;

    ((OpenGLFramebuffer*)self)->destroyFramebuffer();
    ((OpenGLFramebuffer*)self)->contextActive = false;
}


void OpenGLFramebuffer::initContext(void* self)
{
    if(OpenGLGState::getMaxSamples() == 1)
        return;

    if(((OpenGLFramebuffer*)self)->contextActive)
        freeContext(self);

    ((OpenGLFramebuffer*)self)->initFramebuffer();
    ((OpenGLFramebuffer*)self)->contextActive = true;
}


/*
 * Local Variables: ***
 * mode: C++ ***
 * tab-width: 8 ***
 * c-basic-offset: 2 ***
 * indent-tabs-mode: t ***
 * End: ***
 * ex: shiftwidth=2 tabstop=8
 */
